TWI833757B - Coil component and electronic device - Google Patents

Abstract

A coil component includes: a base part containing a magnetic material and having insulating property; a flat coil embedded in the base part, formed by a wound coil conductor where one end part referred to as a first end part is located on an inner side of the windings, and another end part referred to as a second end part is located on an outer side of the windings; a first lead conductor connected to the first end part of the flat coil; a second lead conductor connected to the second end part of the flat coil; a first external electrode provided on a surface of the base part and connected to the first lead conductor; and a second external electrode provided on a surface of the base part and connected to the second lead conductor; wherein the first lead conductor is connected to the first external electrode in an area on an inner side of an outermost periphery coil conductor of the flat coil when the base part and the flat coil are viewed from above in a direction of a coil axis of the flat coil.

Description

Coil parts and electronic equipment

The present invention relates to coil parts and electronic equipment.

As coil components are required to be thinner, the resistance can be reduced by using coil components in high frequency bands (for example, above 10 MHz). Therefore, in recent years, coil parts using a planar coil in which a coil conductor is wound into a single layer of vortex have begun to be used. In a planar coil in which the coil conductor is wound in a spiral shape, one end is located inside the planar coil and the other end is located outside the planar coil. Therefore, a structure is known in which a lead-out conductor connected to an end located inside the planar coil among both ends of the planar coil is led out from the inside of the planar coil to an outside of the planar coil and connected to an external electrode (for example, patent Document 1).

[Prior technical literature] [Patent Document]

[Patent Document 1] Japanese Patent Application Laid-Open No. 2001-102217

When coil parts are used in high-frequency bands, there is a greater demand for low losses. The higher the frequency of use, the faster the magnetic flux passing through the coil conductor and the lead conductor changes. With this, the loss inside the conductor increases due to eddy current.

The present invention was completed in view of the above-mentioned problems, and aims to suppress an increase in losses within a conductor.

The present invention is a coil component, which includes: a base part containing a magnetic material and having insulating properties; a planar coil built in the base part and formed by winding a coil conductor, with the first end of one side located on the circumference. On the inside of the winding, the second end on the other side is located on the outside of the above-mentioned winding; the first lead-out conductor is connected to the above-mentioned first end of the above-mentioned planar coil; the second lead-out conductor is connected to the above-mentioned end of the above-mentioned planar coil a second end portion; a first external electrode provided on the surface of the base portion and connected to the first lead-out conductor; and a second external electrode provided on the surface of the base portion and connected to the second lead-out conductor; The first lead-out conductor is connected to the first external electrode in a region further inside than the planar coil when the base portion and the planar coil are planarly viewed from the coil axial direction of the planar coil.

In the above structure, the first lead-out conductor may be linearly connected from the first end of the planar coil to the first external electrode.

In the above configuration, the first lead-out conductor may be configured to be parallel to the axis of the coil.

In the above configuration, the first lead-out conductor may be configured to overlap the coil conductor when the base portion and the planar coil are viewed from above in the coil axial direction.

In the above-mentioned structure, the cross section of the first lead-out conductor and the second lead-out conductor in a direction perpendicular to the coil axis may be formed into a circular shape.

In the above configuration, the first lead-out conductor may be connected to the first external electrode provided on the first surface of the base part, and the second lead-out conductor may be connected to the first lead conductor provided on the first surface of the base part. The second external electrode is connected, and the first external electrode and the second external electrode are not provided on the second surface of the base part opposite to the first surface.

In the above configuration, the first external electrode and the second external electrode may be provided only on the first surface among the surfaces of the base portion.

In the above configuration, the first external electrode may be configured to extend from the first surface of the surface of the base portion to the above-mentioned surface through a third surface connected to the first surface and the second surface on the side opposite to the first surface. The second external electrode is provided on the second surface of the base portion, and extends from the first surface of the base portion to the second surface via a fourth surface connected to the first surface and the second surface.

In the above structure, it may be configured to include: a third lead conductor connected to the first end of the planar coil; a fourth lead conductor connected to the second end of the planar coil; and a third external electrode, It is provided on the surface of the above-mentioned base part and is connected to the above-mentioned third lead-out conductor; and a fourth external electrode is provided on the surface of the above-mentioned base part and is connected to the above-mentioned fourth lead-out conductor. body; and the first lead-out conductor is connected to the first external electrode provided on the first surface of the base part, and the second lead-out conductor is connected to the second external electrode provided on the first surface of the base part The electrodes are connected, and the third lead-out conductor, when the base portion and the planar coil are viewed from above in the axial direction of the coil, is located in a region further inside than the planar coil and is provided on the side of the base portion opposite to the first surface. The third external electrode on the second surface is connected, and the fourth lead-out conductor is connected to the fourth external electrode provided on the second surface of the base part.

In the above configuration, the first external electrode and the third external electrode may be connected to a third surface of the base portion that is connected to the first surface and the second surface, and the second external electrode and the fourth external electrode may be connected to each other. The external electrode is connected to a fourth surface of the base portion that is connected to the first surface and the second surface.

In the above configuration, the first lead-out conductor may be connected to the first external electrode provided on the first surface of the base part, and the second lead-out conductor may be connected to the first lead conductor provided on the first surface of the base part. The above-mentioned second external electrode is connected, the ends of the above-mentioned first lead-out conductor and the above-mentioned second lead-out conductor protrude from the above-mentioned first surface of the above-mentioned base part, and the above-mentioned first external electrode and the above-mentioned second external electrode are connected by covering the above-mentioned first lead-out conductor. The conductor and the end portion of the second lead-out conductor form a dome-shaped protrusion.

In the above structure, the height of the coil component is 0.6 mm or less.

The present invention is an electronic device including the coil component described above and a circuit board for mounting or integrating the coil component.

According to the present invention, an increase in loss inside the conductor can be suppressed.

10: Base part

12: Lower surface

14: Upper surface

16a, 16b: End face

18a, 18b: side

20: Center line

22:Center

30: Planar coil

32: Coil conductor

33: The outermost part

34:End

36:End

38: Coil shaft

40:Area

42:Area

50, 51, 52, 54, 56: Lead conductor

60, 62, 64, 66: External electrode

65, 67: Noodles

68, 70:Protrusion

80:Substrate

90:Circuit substrate

92: Pad pattern

94:Solder

100, 110, 120, 130: Coil parts

200, 300, 400: Coil parts

500:Electronic machinery

1000: Coil parts

B: Magnetic flux

Ia: current

Ib: eddy current

L1~L4: length

Figure 1 is a perspective view of the coil component of Embodiment 1.

Figure 2(a) is a perspective top view of the coil component of Embodiment 1, and Figure 2(b) is a bottom view.

Fig. 3(a) is a cross-sectional view between A-A in Fig. 1, and Fig. 3(b) is a cross-sectional view between B-B in Fig. 1.

Fig. 4(a) is a perspective view of the coil component of the comparative example, and Fig. 4(b) is a cross-sectional view taken along line A-A in Fig. 4(a).

FIG. 5 is a diagram for explaining the problem of producing the coil component of the comparative example.

6(a) to 6(c) are cross-sectional views of coil components from Modification 1 to Modification 3 of Embodiment 1.

Figure 7 is a cross-sectional view of the coil component of Embodiment 2.

Figure 8 is a cross-sectional view of the coil component of Embodiment 3.

Figure 9 is a cross-sectional view of the coil component of Embodiment 4.

Fig. 10 is a cross-sectional view of the electronic device of Embodiment 5.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Example 1]

Figure 1 is a perspective view of the coil component of Embodiment 1. Figure 2(a) is a perspective top view of the coil component of Embodiment 1, and Figure 2(b) is a bottom view. In addition, the external electrode is omitted in Figure 2(a) As shown in Figure 2(b), the cross-section of the external electrode and other illustrated lead conductors is seen through. Fig. 3(a) is a cross-sectional view between A-A in Fig. 1, and Fig. 3(b) is a cross-sectional view between B-B in Fig. 1. As shown in FIGS. 1 , 2(a) and 2(b) and 3(a) and 3(b) , the coil component 100 of Embodiment 1 includes a base part 10 and a planar coil built in the base part 10 30. The lead-out conductors 50 and 52 drawn out from the end of the planar coil 30, and the external electrodes 60 and 62 provided on the surface of the base part 10.

The base portion 10 has a rectangular parallelepiped shape having a lower surface 12, an upper surface 14, a pair of end surfaces 16a and 16b, and a pair of side surfaces 18a and 18b. The lower surface 12 is the mounting surface, and the upper surface 14 is the surface opposite to the lower surface 12 . The end surfaces 16a and 16b are surfaces connected to the short sides of the lower surface 12 and the upper surface 14, and the side surfaces 18a and 18b are surfaces connected to the long sides of the lower surface 12 and the upper surface 14. In addition, the base portion 10 is not limited to a complete rectangular parallelepiped shape. For example, each vertex may have an arc, each edge (boundary portion of each surface) may have an arc, or each surface may have a curved surface. wait. That is, the rectangular parallelepiped shape also includes this shape.

The base portion 10 has insulating properties and is formed by containing magnetic particles such as magnetic metal particles or ferrite particles. The base portion 10 is formed by including, for example, magnetic particles as a main component. The term "containing the main component" means, for example, that the composition contains more than 50 wt% of magnetic particles, 70 wt% or more of magnetic particles, or 80 wt% or more of magnetic particles. The base part 10 may be formed of resin containing magnetic particles, or may be formed of magnetic particles whose surface is insulatingly coated. As the magnetic metal particles, for example, magnetic metals such as FeSi-based, FeSiCr-based, FeSiAl-based, FeSiCrAl-based, Fe or Ni, crystalline magnetic metals, amorphous magnetic metals or nanocrystalline magnetic metals are used. As the ferrite particles, for example, NiZn-based ferrite or MnZn-based ferrite is used. As the resin, thermosetting resins such as polyimide or phenol resin can be used, and polyethylene resin, polyamide resin, etc. can also be used. Thermosetting resin. As the insulating film covering the surface of the magnetic particles, an inorganic insulating film such as a silicon oxide film can also be used.

The planar coil 30 is formed by winding a coil conductor 32 in a spiral shape. One end 34 of the coil conductor 32 is arranged inside the winding, and the other end 36 is arranged outside the winding. It is also called a planar coil 30. Planar spiral coil. The end portion 34 and the end portion 36 may be located on a straight line that passes through the center of the planar coil 30 in plan view and is substantially parallel to the long sides of the lower surface 12 and the upper surface 14 , or either or both may deviate from the straight line. The coil conductor 32 is made of, for example, metal materials such as copper, aluminum, nickel, silver, platinum or palladium or alloy materials containing these, and an insulating film may also be provided on the surface of the conductor. The cross-sectional shape of the coil conductor 32 is, for example, a rectangular shape, but may also be a trapezoidal shape, a semi-elliptical shape including a straight line and a curve, or the like. The planar coil 30 has a coil axis 38 orthogonal to the plane defined by the circumference of the coil conductor 32 . The lower surface 12 and the upper surface 14 of the base portion 10 are substantially orthogonal to the coil axis 38 , and the end surfaces 16 a and 16 b and side surfaces 18 a and 18 b of the base portion 10 are substantially parallel to the coil axis 38 . The coil conductor 32 has gaps between each turn. The gap can be a space, an insulating film of the coil conductor 32, or other insulators, as long as each circumference is insulated.

The planar coil 30 may be formed into an elliptical shape by, for example, surrounding the coil conductor 32 in an elliptical shape. However, the planar coil 30 may also be formed into a circular shape by surrounding the coil conductor 32 in a circular shape, or may be formed in a rectangular shape by surrounding the coil conductor 32 . It has a rectangular shape, or it can also have a so-called rugby shape by winding the coil conductor 32 in these composite shapes. Here, the shape of the planar coil 30 , that is, the surrounding shape of the coil conductor 32 is regarded as a figure in which the conductor of the outermost peripheral portion of the coil conductor 32 is closed, and can be expressed as an elliptical shape, a circular shape, a rectangular shape, or a rugby ball shape. Hereinafter, the shape of the planar coil 30 , that is, the circumferential shape of the coil conductor 32 will be shown in the same manner. Furthermore, it is assumed that the minor axis length L2 of the planar coil 30 is When the ratio of the major axis lengths L1 (L2/L1) is 0.9 or less, the planar coil 30 has an elliptical shape, and when it exceeds 0.9, the planar coil 30 has a circular shape. Furthermore, when the length in the long side direction of the base portion 10 is L3 and the length in the short side direction is L4, the ratio between the long axis length L1 and the short axis length L2 of the planar coil 30 is equal to that of the base portion 10 The ratio of the length L3 in the long side direction to the length L4 in the short side direction is preferably substantially the same (L1: L2≒L3: L4). The coil axis 38 is defined as an axis perpendicularly passing through the center of a conductor-enclosed figure considering the circumferential shape of the coil conductor 32 as the outermost peripheral portion of the coil conductor 32 . When the circumferential shape of the coil conductor 32 is an ellipse, the center of the circumferential shape of the coil conductor 32 is the intersection of the long axis and the short axis; when the circumferential shape of the coil conductor 32 is a rectangle, the center of the circumferential shape of the coil conductor 32 is a rectangle. The center of the circumferential shape is the intersection point of the diagonals; when the circumferential shape of the coil conductor 32 is a rugby ball shape, the center of the circumferential shape of the coil conductor 32 is the center point that bisects the axis of symmetry.

Since the planar coil 30 has a so-called single-layer spiral winding shape in which the coil conductor 32 does not overlap in the direction of the coil axis 38, the coil component 100 can be made thinner. For example, the height of the coil component 100 can be set to 0.6 mm or less, 0.4 mm or less, or 0.2 mm or less. Examples of the size (length × width × height) of the coil component 100 include 0.2 mm × 0.1 mm × 0.1 mm, 0.3 mm × 0.2 mm × 0.1 mm, 0.3 mm × 0.2 mm × 0.2 mm, and 0.4 mm × 0.2 mm. ×0.2mm, 0.6mm×0.3mm×0.3mm, 1.0mm×0.5mm×0.3mm, 1.6mm×0.8mm×0.3mm, 1.6mm×0.8mm×0.4mm, 1.6mm×0.8mm×0.5mm, 1.6 mm×1.0mm×0.3mm, 1.6mm×1.0mm×0.4mm, 1.6mm×1.0mm×0.5mm, 1.6mm×1.2mm×0.3mm, 1.6mm×1.2mm×0.4mm, 1.6mm×1.2mm× 0.5mm, 2.0mm×1.2mm×0.3mm, 2.0mm×1.2mm×0.4mm, 2.0mm×1.2mm×0.5mm, 2.0mm×1.2mm×0.6mm, 2.0mm×1.6mm× 0.3mm, 2.0mm×1.6mm×0.5mm, etc.

The external electrodes 60 and 62 are surface-mounted external terminals, and are located at portions that overlap the end portions 34 and 36 of the coil conductor 32 when viewed from the direction of the coil axis 38 . The external electrode 60 is provided on the lower surface 12 of the base portion 10 close to the end surface 16a. The external electrode 62 is provided on the lower surface 12 of the base portion 10 close to the end surface 16b. The external electrodes 60 and 62 are only provided on the lower surface 12 among the surfaces of the base portion 10, and are not provided on the upper surface 14, end surfaces 16a and 16b, and side surfaces 18a and 18b. That is, the external electrodes 60 and 62 are single-surface electrodes provided on only one surface of the base portion 10 . The external electrodes 60 and 62 are arranged symmetrically with respect to, for example, the center line 20 between the end surfaces 16 a and 16 b of the base portion 10 . The external electrodes 60 and 62 may also be disposed symmetrically with respect to, for example, the center 22 of the lower surface 12 of the base portion 10 . By arranging the external electrodes 60 and 62 symmetrically with respect to the center line 20 and/or the center 22 , the coil component 100 can be mounted on a circuit board or the like in a well-balanced manner.

The external electrodes 60 and 62 use, for example, a lower layer made of a metal material such as copper, aluminum, nickel, silver, platinum or palladium or an alloy material containing these, an intermediate layer made of silver or a conductive resin containing silver, and nickel, The plating of tin or copper is the multi-layer structure of the upper layer. In addition, when there is an intermediate layer between each layer or when there is an uppermost layer above the upper layer, the layer structure of the external electrodes 60 and 62 is not limited to the illustrated case.

Here, when the planar coil 30 is viewed from the direction of the coil axis 38 , the area enclosed by a curve closed so that the outermost peripheral portion 33 of the coil conductor 32 has the shortest circumference is defined as the area 42 ( FIG. 2 (The slashed part of (a)). The lead conductor 50 is bent in the direction from the coil axis 38 When viewing the planar coil 30 , it is only located inside the area 42 and connects the end 34 of the planar coil 30 and the external electrode 60 provided on the lower surface 12 of the base portion 10 . That is, the conductor 50 is drawn out in the area between the lower surface 12 and the upper surface 14 of the base portion 10 with the area 42 as the cross section (in other words, between the lower surface 12 and the upper surface 14 of the base portion 10 with the area 42 interposed therebetween). When the area) is set to the area 40 (the area within the thick solid line in Figure 3 (a) and Figure 3 (b)), it is only located inside the area 40 and connects the end 34 of the planar coil 30 and the base portion 10 External electrode 60 on lower surface 12 .

The lead-out conductor 50 may also linearly connect the end 34 of the planar coil 30 and the external electrode 60 provided on the lower surface 12 of the base part 10 . Thereby, since the length of the lead-out conductor 50 is shortened, the resistance can be reduced. In addition, the lead conductor 50 may be parallel to the coil axis 38 and connect the end 34 of the planar coil 30 and the external electrode 60 provided on the lower surface 12 of the base part 10 . Thereby, since the length of the lead-out conductor 50 is further shortened, the resistance is further reduced, which can effectively suppress the influence of eddy currents described below. In addition, "parallel to the coil axis 38" means that both ends of the lead conductor 50 overlap when viewed from the direction of the coil axis 38. The shortest length is achieved as long as at least half of each end overlaps. In addition, the term "parallel to the coil axis 38" is not limited to parallel in a strict sense, but may also include slight inclination and/or step differences to the extent of manufacturing errors. In addition, the lead conductor 50 may be configured to overlap the coil conductor 32 when viewed from the direction of the coil axis 38 . That is, the lead conductor 50 may be arranged so as to be limited within the width of the coil conductor 32 . Thereby, the connection stability of the lead conductor 50 and the coil conductor 32 becomes better, and the connection resistance can be made constant regardless of the positional deviation of a connection part.

The lead-out conductor 52 may also linearly connect the end 36 of the planar coil 30 and the external electrode 62 provided on the lower surface 12 of the base part 10 . Thereby, the resistance of the lead-out conductor 52 can be reduced. The lead-out conductor 52 may also be parallel to the coil axis 38 and connect the end 36 of the planar coil 30 and be disposed under the base part 10 External electrode 62 on surface 12 . Thereby, the resistance of the lead-out conductor 52 can be further reduced. Moreover, the lead-out conductor 52 may be connected to the external electrode 62 on the end surface 16b of the base part 10 like a general structure.

The lead-out conductors 50 and 52 are formed of, for example, metal materials such as copper, aluminum, nickel, silver, platinum, or palladium, or alloy materials containing these. The lead-out conductors 50 and 52 and the coil conductor 32 may be formed of the same material or may be formed of different materials. The cross-sectional shape of the lead conductors 50 and 52 in the direction perpendicular to the coil axis 38 is, for example, a circular shape. Accordingly, even when the number of windings of the coil conductor 32 is set to an arbitrary value, the magnetic flux passing through the lead-out conductors 50 and 52 can be made approximately constant, so that the influence of the loss can be made constant. The diameters of the lead-out conductors 50 and 52 are, for example, about 50 μm to 300 μm. In addition, the cross-sectional shape of the lead-out conductors 50 and 52 in the direction perpendicular to the coil axis 38 may be an elliptical shape, a rectangular shape, or the like, in addition to the circular shape.

Here, the manufacturing method of the coil component 100 of Example 1 is demonstrated. The coil component 100 is formed by a step including laminating a plurality of green sheets (insulating sheets). The green sheet is an insulating precursor constituting the base portion 10 and is formed by applying a resin material containing magnetic particles on a film by, for example, a doctor blade method or a printing method.

First, prepare multiple raw and bad pieces. Through-holes are formed on some of the plurality of green wafers by performing laser processing or etching processing at specific positions. Next, a conductive material is coated on the green sheet with the through hole formed by using, for example, a printing method to form a precursor for the coil conductor 32 and the lead-out conductors 50 and 52 constituting the planar coil 30 . In addition, on other green sheets where through holes are formed, a conductive material is coated using, for example, a printing method to form precursors for lead conductors 50 and 52 . The precursors are fired to become the coil conductor 32 and lead conductors 50 and 52 .

Secondly, a plurality of raw and defective sheets are stacked in a specific order, and pressure is applied to the plurality of raw and defective sheets in the direction of lamination. Then, the pressed green wafer is cut into wafer units using a cutter or a guillotine, and then fired at a specific temperature. By this firing, the base portion 10 in which the planar coil 30 made of the coil conductor 32 and the lead-out conductors 50 and 52 are provided is formed. Next, external electrodes 60 and 62 are formed on the lower surface 12 of the base portion 10 . The external electrodes 60 and 62 are formed by paste printing or plating, sputtering, or other methods used in thin film manufacturing processes.

Next, the coil parts of the comparative example will be described. Fig. 4(a) is a perspective view of the coil component of the comparative example, and Fig. 4(b) is a cross-sectional view taken along line A-A in Fig. 4(a). As shown in FIGS. 4(a) and 4(b) , in the coil component 1000 of the comparative example, the leads connected to the ends 36 located outside the planar coil 30 among the two ends 34 and 36 of the planar coil 30 The conductor 52 linearly connects the end portion 36 of the planar coil 30 and the external electrode 62 provided on the lower surface 12 of the base portion 10 in the same manner as in the first embodiment. On the other hand, the lead conductor 51 connected to the end portion 34 located inside the planar coil 30 is led out from the end portion 34 of the planar coil 30 to the lower surface 12 side of the base portion 10 and then bent to be led out from the inside to the outside of the planar coil 30 . The lead conductor 51 is led out to the outside of the planar coil 30 and then bent again to be led out to the lower surface 12 of the base part 10 , and is connected to the external electrode 60 on the lower surface 12 of the base part 10 . Since other configurations are the same as those in Embodiment 1, description is omitted.

In the coil component 1000 of the comparative example, the lead-out conductor 51 connected to the end portion 34 of the planar coil 30 is led out from the inside of the planar coil 30 to the outside of the planar coil 30 in the base portion 10 . Therefore, the lead conductor 51 intersects all of the surrounding coil conductor 32 . Thereby, the magnetic flux generated by the current flowing through the lead conductor 51 passes through the portion of the coil conductor 32 that intersects the lead conductor 51 In this case, an eddy current is generated in the coil conductor 32 as a result. Use Figure 5 to illustrate this point.

FIG. 5 is a diagram for explaining the problems caused by the coil component of the comparative example. In addition, in FIG. 5 , for clarity of the drawing, one of the plurality of turns of the coil conductor 32 intersecting the lead conductor 51 is shown. As shown in FIG. 5 , the magnetic flux B is generated by flowing the current Ia through the lead conductor 51 . The current Ia flows because it is repeatedly turned on and off, so the magnetic flux B changes due to the increase or decrease of the current Ia. Since the lead conductor 51 crosses the coil 32 and is led out, the magnetic flux B generated in the lead conductor 51 passes through the coil conductor 32 . As the magnetic flux B passing through the coil conductor 32 changes, an eddy-shaped induced current, that is, eddy current Ib, is generated in the coil conductor 32 . If the eddy current Ib is generated in the coil conductor 32, the energy loss will increase due to the resistance of the coil conductor 32, that is, the loss inside the coil conductor 32 due to the eddy current will increase. As the coil component is used in a high-frequency band, the current Ia flowing through the lead conductor 51 is switched on and off quickly, so the change of the magnetic flux B generated in the lead conductor 51 becomes faster. Therefore, the loss inside the coil conductor 32 caused by the eddy current generated in the coil conductor 32 becomes larger. On the contrary, if the magnetic flux generated by the coil conductor 32 passes through the lead conductor 51, the loss inside the lead conductor 51 caused by the eddy current will also increase. In addition, in the entire portion where the plurality of turns of the coil conductor 32 intersects the lead conductor 51, losses within the conductor due to eddy currents occur on both the lead conductor 51 side and the coil conductor 32 side.

On the other hand, according to Embodiment 1, as shown in FIGS. 1 and 2(a) , when the base portion 10 and the planar coil 30 are viewed from the direction of the coil axis 38 of the planar coil 30 , the lead conductor 50 is smaller than the planar coil 30 . The inner region 42 is connected to the external electrode 60 . Thereby, the intersection portion of the lead conductor 50 and the coil conductor 32 can be reduced. Therefore, the eddy current generated due to the magnetic flux generated in the lead conductor 50 passing through the coil conductor 32 and the magnetic flux generated in the coil conductor 32 passing through the lead conductor 50 can be reduced. It can suppress the increase of losses inside the conductor caused by eddy current.

The lead-out conductor 50 is preferably a straight line connecting the end 34 of the planar coil 30 and the external electrode 60 provided on the lower surface 12 of the base portion 10 . Thereby, the eddy current generated by the coil conductor 32 and the lead conductor 50 can be effectively reduced. In addition, the resistance of the lead-out conductor 50 can also be reduced.

The lead-out conductor 50 is preferably as shown in FIG. 3(a) , parallel to the coil axis 38 of the planar coil 30 and linearly connecting the end 34 of the planar coil 30 and the external electrode 60 provided on the lower surface 12 of the base part 10 . Thereby, since the intersection of the lead conductor 50 and the coil conductor 32 is suppressed, the eddy current generated in the coil conductor 32 and the lead conductor 50 can be more effectively reduced. In addition, since the length of the lead-out conductor 50 becomes shorter, the resistance becomes smaller, and therefore the influence of eddy currents can also be suppressed in this regard.

The lead-out conductor 50 is preferably arranged to overlap the coil conductor 32 when the base portion 10 and the planar coil 30 are viewed from the direction of the coil axis 38 as shown in FIG. 3(a) . Thereby, the connection stability of the lead conductor 50 and the coil conductor 32 becomes better, and the connection resistance can be made constant regardless of the positional deviation of a connection part.

As shown in FIGS. 1 and 3(a) , it is preferable that the lead-out conductor 52 connects the end portion 36 of the planar coil 30 and the external electrode 62 provided on the lower surface 12 of the base portion 10 . The external electrodes 60 and 62 are provided on the lower surface 12 of the base portion 10 and are not provided on the upper surface 14 . Thereby, the coil component 100 can be made thinner. It is further preferred that the external electrodes 60 and 62 are provided only on the lower surface 12 among the surfaces of the base portion 10 and are not provided on surfaces other than the lower surface 12 . This prevents solder from adhering to the end surfaces 16a and 16b and the side surfaces 18a and 18a of the base portion 10 when the coil component 100 is mounted on the circuit board. 18b, so in addition to thinning the coil component 100, it can also cope with high-density mounting.

As shown in FIG. 2(b) , the cross-sectional shape of the lead conductors 50 and 52 in the direction perpendicular to the coil axis 38 is preferably circular. Accordingly, even if the formation positions of the lead conductors 50 and 52 change according to the degree of winding of the coil conductor 32, the magnetic flux generated in the coil conductor 32 and passing through the lead conductors 50 and 52 is set to be approximately constant. The losses inside the lead conductors 50 and 52 caused by the eddy current generated in the lead conductors 50 and 52 are assumed to be constant. Furthermore, preferably, the width of the coil conductor 32 is greater than the distance between the conductors surrounding the coil conductor 32 , and the width of the coil conductor 32 is greater than the height of the coil conductor 32 . Therefore, when viewed from the direction of the coil axis 38 , which is the spaced-apart portion of the conductors surrounding the coil conductor 32 , even in the area overlapping the planar coil 30 , magnetic material may exist penetrating in the direction of the coil axis 38 . The eddy current generated between the coil conductors 32 is reduced.

As shown in FIG. 2(b) , the external electrodes 60 and 62 are preferably arranged symmetrically with respect to the center line 20 and/or the center 22 of the lower surface 12 of the base portion 10 . Thereby, the coil component 100 can be mounted on a circuit board or the like in a well-balanced manner. In addition, the distance between the external electrode 60 and the external electrode 62 is preferably, for example, 100 μm or more, more preferably 150 μm or more, and still more preferably 200 μm or more, from the viewpoint of short circuit suppression, ease of manufacturing, etc. condition.

6(a) to 6(c) are cross-sectional views of coil components from Modification 1 to Modification 3 of Embodiment 1. As shown in FIG. 6(a) , in the coil component 110 of Modification 1 of Embodiment 1, the external electrodes 60 and 62 extend from the lower surface 12 of the base part 10 to the end surfaces 16a and 16b. Since other configurations are the same as those in Embodiment 1, description is omitted. As in Modification 1 of Embodiment 1, by extending the external electrodes 60 and 62 Extending to the end surfaces 16a and 16b of the base part 10, when the coil component 110 is soldered to the circuit board, solder pieces are formed on the external electrodes 60 and 62 provided on the end surfaces 16a and 16b of the base part 10. Therefore, the bonding strength between the coil component 110 and the circuit board can be improved.

As shown in FIG. 6(b) , in the coil component 120 of Modification 2 of Embodiment 1, the lead conductor 50 is led out from the end 34 of the planar coil 30 to the lower surface 12 of the base part 10, between the lower surface 12 and the outside. Electrode 60 is connected. The lead-out conductor 52 is led out from the end 36 of the planar coil 30 to the upper surface 14 of the base portion 10 and is connected to the external electrode 62 on the upper surface 14 . The external electrode 60 extends from the lower surface 12 of the base portion 10 to the upper surface 14 via the end surface 16 a, and the external electrode 62 extends from the lower surface 12 of the base portion 10 to the upper surface 14 via the end surface 16 b. That is, the external electrodes 60 and 62 become three-surface electrodes. In addition, the external electrodes 60 and 62 may also be five-sided electrodes extending to the side surfaces 18a and 18b. In addition, the lead-out conductor 52 may also extend from the end 36 of the planar coil 30 to the lower surface 12 of the base part 10 and be connected to the external electrode 62 on the lower surface 12 . Since other configurations are the same as those in Embodiment 1, description is omitted.

According to Modification 2 of Embodiment 1, the external electrode 60 connected to the lead-out conductor 50 is provided extending from the lower surface 12 of the base portion 10 to the upper surface 14 via the end surface 16 a. The external electrode 62 connected to the lead-out conductor 52 is provided extending from the lower surface 12 of the base portion 10 to the upper surface 14 via the end surface 16 b. Thereby, both the lower surface 12 and the upper surface 14 of the base portion 10 can be used as mounting surfaces.

As shown in FIG. 6(c) , in the coil component 130 of Modification 3 of Embodiment 1, a lead conductor 54 is connected to the end 34 of the planar coil 30 in addition to the lead conductor 50 . The lead conductor 54 is located only inside the area 42 (see FIG. 2(a) ) when viewed from the direction of the coil axis 38 , and connects the end 34 of the planar coil 30 and the external electrode 64 provided on the upper surface 14 of the base portion 10 . for planar coils In addition to the lead-out conductor 52, the end 36 of the end 30 is also connected to a lead-out conductor 56. The lead-out conductor 56 connects the end portion 36 of the planar coil 30 and the external electrode 66 provided on the upper surface 14 of the base portion 10 . Since other configurations are the same as those of the first embodiment, description is omitted.

According to Modification 3 of Embodiment 1, the lead-out conductor 50 and the lead-out conductor 54 are connected to the end portion 34 of the planar coil 30 , and the lead-out conductor 52 and the lead-out conductor 56 are connected to the end portion 36 . When the base portion 10 and the planar coil 30 are viewed from the direction of the coil axis 38 of the planar coil 30, the lead conductor 50 is connected to the external electrode 60 provided on the lower surface 12 of the base portion 10 in the region 42 further inside than the planar coil 30. The inner region 42 of the lead-out conductor 54 is connected to the external electrode 64 provided on the upper surface 14 of the base portion 10 . Furthermore, the lead conductor 52 is connected to the external electrode 62 provided on the lower surface 12 of the base part 10 , and the lead conductor 56 is connected to the external electrode 66 provided on the upper surface 14 of the base part 10 . Thereby, both the lower surface 12 and the upper surface 14 of the base portion 10 can be used as mounting surfaces.

The external electrodes 60, 62, 64 and 66 are preferably provided on the lower surface 12 and the upper surface 14 of the base portion 10, and are not provided on surfaces other than the lower surface 12 and the upper surface 14. This makes it possible to cope with high-density mounting for the same reason as described in Embodiment 1. In addition, in Modification 3 of Embodiment 1, similarly to Modification 2 of Embodiment 1, the external electrodes provided on the surface of the base portion 10 may be three-surface electrodes or five-surface electrodes. That is, the external electrode 60 provided on the lower surface 12 of the base part 10 and the external electrode 64 provided on the upper surface 14 are connected at the end surface 16 a, and the external electrode 62 provided on the lower surface 12 of the base part 10 is connected to the external electrode 64 provided on the upper surface 14 The external electrode 66 may also be connected to the end surface 16b.

[Example 2]

Figure 7 is a cross-sectional view of the coil component of Embodiment 2. As shown in Figure 7, the coil in Example 2 In the component 200, a substrate 80 with a coil conductor 32 formed on the main surface is built into the base portion 10. Since other configurations are the same as those in Embodiment 1, description is omitted. The coil component 200 of Example 2 is manufactured by, for example, the following method. First, the coil conductor 32 is formed on the main surface of the substrate 80 which is an insulating substrate such as a glass substrate, using a plating method, for example. Furthermore, the base portion 10 is formed on both main surfaces of the substrate 80 on which the coil conductor 32 is formed, for example, by a lamination method or a voltage equalizing method. Thereby, the base portion 10 in which the substrate 80 having the coil conductor 32 is built is obtained. Furthermore, after a hole is formed in the lower surface 12 of the base part 10 by, for example, laser processing or etching to expose both ends 34 and 36 of the planar coil 30, a conductive material is buried in the hole by, for example, printing. Thus, lead conductors 50 and 52 are formed. Thereafter, external electrodes 60 and 62 are formed on the lower surface 12 of the base portion 10 .

Like the coil component 200 of Embodiment 2, the substrate 80 with the coil conductor 32 formed on the main surface may be incorporated in the base portion 10 . In this case, since the substrate 80 exists on the upper surface of the coil conductor 32, there is no magnetic material on the entire upper surface of the planar coil 30. That is, when viewed from the direction of the coil axis 38 , there is no magnetic material penetrating the area overlapping the planar coil 30 . Therefore, the generation of eddy current in the coil conductor 32 can be effectively suppressed.

[Example 3]

Figure 8 is a cross-sectional view of the coil component of Embodiment 3. As shown in FIG. 8 , in the coil component 300 of the third embodiment, the coil conductor 32 is made of a coated wire and has a circular cross-sectional shape. The lead conductors 50 and 52 are formed by shaping (bending) the wire forming the coil conductor 32 . That is, the coil conductor 32 and the lead conductors 50 and 52 have the same diameter and cross-sectional shape. Since other configurations are the same as those in Embodiment 1, description is omitted. The coil component 300 of Example 3 is manufactured by, for example, the following method. First, the coated wire is wound to form the coil conductor 32, and the wound conductor 32 is The lead conductors 50 and 52 are formed by performing forming processing (bending processing) on both end sides of the conductor. Then, the base portion 10 in which the coil conductor 32 and the lead-out conductors 50 and 52 are built is formed by, for example, a lamination method or a voltage equalizing method. At this time, the end surfaces of the lead-out conductors 50 and 52 are exposed from the lower surface 12 of the base part 10 . Thereafter, external electrodes 60 and 62 are formed on the lower surface 12 of the base portion 10 .

Like the coil component 300 of Embodiment 3, the lead conductors 50 and 52 may be formed by forming the wires forming the coil conductor 32 . In this case, there is no magnetic material between coil conductors 32 . That is, in a cross section perpendicular to the direction of the coil axis 38 , there is no magnetic material penetrating between the surrounding conductors of the planar coil 30 in a direction parallel to the coil axis 38 . Therefore, the generation of eddy current in the coil conductor 32 can be effectively suppressed. In addition, the conductive wire is not limited to a round wire having a circular cross-section, but may also be a rectangular wire having a rectangular cross-section.

[Example 4]

Figure 9 is a cross-sectional view of the coil component of Embodiment 4. As shown in FIG. 9 , in the coil component 400 of the fourth embodiment, the ends of the lead conductors 50 and 52 protrude from the lower surface 12 of the base part 10 . The amount of protrusion of the lead-out conductors 50 and 52 from the lower surface 12 of the base part 10 is, for example, about 5 μm to 20 μm. The external electrode 60 is formed to cover the end portion of the lead conductor 50 protruding from the lower surface 12 of the base portion 10, thereby forming a dome-shaped protrusion 68. That is, the external electrode 60 has a surface 65 that is substantially parallel to the lower surface 12 of the base portion 10 and a dome-shaped protrusion 68 that bulges on the opposite side to the lower surface 12 of the base portion 10 based on the substantially parallel surface 65 . Similarly, the external electrode 62 is formed to cover the end portion of the lead conductor 52 protruding from the lower surface 12 of the base portion 10, thereby forming a dome-shaped protrusion 70. That is, the external electrode 62 has a surface 67 that is substantially parallel to the lower surface 12 of the base portion 10 and is substantially parallel to the lower surface 12 of the base portion 10 based on the substantially parallel surface 67 . A dome-shaped protrusion 70 raised on the opposite side. In addition, the substantially parallel surfaces mentioned here are not limited to those that are parallel in a strict sense, and may also include slight inclination to the extent of manufacturing error. In addition, the dome-shaped protrusion refers to a protrusion in a shape in which the height of the protrusion is lower at the outer peripheral portion of the protrusion, and the height of the protrusion becomes higher closer to the central portion of the protrusion. Since other configurations are the same as those in Embodiment 1, description is omitted.

The coil component 400 of Embodiment 4 can be formed using the same manufacturing method as described in Embodiment 1, for example. At this time, by using a material that has a smaller amount of shrinkage during firing than the insulating material used to form the base portion 10 as the conductive material used to form the lead conductors 50 and 52, the lead conductors 50 and 52 can be obtained. The end portion protrudes from the lower surface 12 of the base portion 10 .

According to Embodiment 4, the ends of the lead-out conductors 50 and 52 protrude from the lower surface 12 of the base portion 10 . The external electrodes 60 and 62 form dome-shaped protrusions 68 and 70 by covering the end portions of the lead conductors 50 and 52 protruding from the lower surface 12 of the base portion 10 . Thereby, when the external electrodes 60 and 62 are pressed against the solder provided on the circuit board in order to mount the external electrodes 60 and 62 on the circuit board, the protrusions 68 and 70 bite into the solder. Therefore, even when the coil component 400 is subjected to situations such as vibration when the pick-up device is lifted by vacuum breaking or vibration when the circuit board is transported to the melting furnace, the coil component 400 can be suppressed from being displaced from a specific position.

[Example 5]

Fig. 10 is a cross-sectional view of the electronic device of Embodiment 5. As shown in FIG. 10 , the electronic device 500 of the fifth embodiment includes a circuit substrate 90 and the coil component 100 of the first embodiment mounted on the circuit substrate 90 . Pad diagram of coil component 100 bonded to circuit board 90 via external electrodes 60 and 62 using solder 94 case 92, and is mounted on the circuit substrate 90.

In addition, in Embodiment 5, although the coil component 100 of Embodiment 1 is mounted on the circuit board 90, it may also be a case where the coil components of Modification 1 to 4 of Embodiment 1 are mounted on the circuit board 90. . For example, by mounting the coil component 400 on the circuit board 90 in Embodiment 4, as described in Embodiment 4, positional misalignment when the coil component 400 is mounted on the circuit board 90 is suppressed. In addition, the coil components can also be incorporated into the circuit board 90, and in any case, the thickness can be reduced.

The embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific embodiments, and various modifications/changes are possible within the scope of the gist of the present invention described in the patent claims.

10‧‧‧Base part

12‧‧‧Lower surface

14‧‧‧Upper surface

16a, 16b‧‧‧End face

18a, 18b‧‧‧Side

30‧‧‧Planar coil

32‧‧‧Coil conductor

34‧‧‧End

36‧‧‧End

50, 52‧‧‧lead conductor

60, 62‧‧‧External electrode

100‧‧‧Coil parts

Claims (13)

A coil component, which includes: a base portion containing a magnetic material and having insulating properties; a planar coil built into the base portion and formed by winding a coil conductor, with the first end of one side located inside the winding , the second end on the other side is located outside the above-mentioned circumference; the first lead-out conductor is connected to the above-mentioned first end of the above-mentioned planar coil; the second lead-out conductor is connected to the above-mentioned second end of the above-mentioned planar coil part; a first external electrode at one end of the base part, disposed on the surface of the base part and connected to the first lead-out conductor; and a second external electrode at the other end opposite to the one end of the base part , is provided on the surface of the above-mentioned base part and is connected to the above-mentioned second lead-out conductor; and the above-mentioned first lead-out conductor is further inside than the above-mentioned planar coil when the above-mentioned base part and the above-mentioned planar coil are viewed from above in the coil axial direction of the above-mentioned planar coil. The region is connected to the first external electrode, and the first external electrode and the second external electrode are arranged symmetrically with respect to a center line, or symmetrically with respect to a center point of the center line, and the center line defines the above-mentioned position of the base portion. At the midpoint between one end and the other end, the outer circumference of the above-mentioned planar coil when viewed from the axial direction of the above-mentioned planar coil has: specified by the ratio of the length L1 of the long axis of the above-mentioned planar coil to the length L2 of the short axis The outer periphery of the base portion when viewed from the axial direction of the coil has a shape specified by the ratio of the length L3 of the base portion in the long side direction to the length L4 in the short side direction, and relative to The ratio of length L1 to length L2 (L2/L1) and the ratio of length L4 to length L3 The rates (L4/L3) are roughly the same. A coil component, which includes: a base portion containing a magnetic material and having insulating properties; a planar coil built into the base portion and formed by winding a coil conductor, with the first end of one side located inside the winding , the second end on the other side is located outside the above-mentioned circumference; the first lead-out conductor is connected to the above-mentioned first end of the above-mentioned planar coil; the second lead-out conductor is connected to the above-mentioned second end of the above-mentioned planar coil part; a first external electrode, which is provided on the surface of the above-mentioned base part and connected to the above-mentioned first lead-out conductor; and a second external electrode, which is provided on the surface of the above-mentioned base part and connected to the above-mentioned second lead-out conductor; and the above-mentioned third 1. When the base portion and the planar coil are viewed from above in the coil axial direction of the planar coil, the lead-out conductor is connected to the first external electrode in a region further inside than the planar coil. The first external electrode extends from the surface of the base portion. The first surface is provided extending to the second surface via a third surface connected to the first surface and the second surface opposite to the first surface, and the second external electrode is formed from the third surface of the base portion. The 1st surface is provided extending to the 2nd surface via the 4th surface connected to the 1st surface and the 2nd surface. A coil component, which includes: a base part that contains a magnetic material and has insulating properties; a planar coil that is built into the base part and is formed by winding a coil conductor. One end is located inside the above-mentioned winding, and the second end on the other side is located outside the above-mentioned winding; the first lead-out conductor is connected to the above-mentioned first end of the above-mentioned planar coil; the second lead-out conductor is connected to the second end of the planar coil; a third lead conductor connected to the first end of the planar coil; a fourth lead conductor connected to the second end of the planar coil; a first external electrode , which is provided on the surface of the above-mentioned base part and is connected to the above-mentioned first lead-out conductor; and a second external electrode which is provided on the surface of the above-mentioned base part and is connected to the above-mentioned second lead-out conductor; a third external electrode which is provided on the above-mentioned lead-out conductor The surface of the base part and connected to the above-mentioned third lead-out conductor; and the fourth external electrode, which is provided on the surface of the above-mentioned base part and connected to the above-mentioned fourth lead-out conductor; and the above-mentioned first lead-out conductor is connected from the above-mentioned planar coil When the base portion and the planar coil are viewed from above in the axial direction of the coil, the first external electrode is connected to the first external electrode provided on the first surface of the surface of the base portion in a region further inside than the planar coil, and the second lead-out conductor is connected to The second external electrode provided on the first surface of the base part is connected to the third lead-out conductor in a region further inside than the planar coil when the base part and the planar coil are viewed from above in the axial direction of the coil. , is connected to the third external electrode provided on the second surface of the base part opposite to the first surface, and the fourth lead-out conductor is connected to the fourth external electrode provided on the second surface of the base part . The coil component of claim 3, wherein the first external electrode and the third external electrode are connected to a third surface of the base portion on the first surface and the second surface, and the second external electrode is connected to the third surface of the base portion. The fourth external electrode is connected to a fourth surface of the base portion that is connected to the first surface and the second surface. A coil component, which includes: a base portion containing a magnetic material and having insulating properties; a planar coil built into the base portion and formed by winding a coil conductor, with the first end of one side located inside the winding , the second end on the other side is located outside the above-mentioned circumference; the first lead-out conductor is connected to the above-mentioned first end of the above-mentioned planar coil; the second lead-out conductor is connected to the above-mentioned second end of the above-mentioned planar coil part; a first external electrode, which is provided on the surface of the above-mentioned base part and connected to the above-mentioned first lead-out conductor; and a second external electrode, which is provided on the surface of the above-mentioned base part and connected to the above-mentioned second lead-out conductor; and the above-mentioned third 1. When the above-mentioned base part and the above-mentioned planar coil are viewed from the coil axial direction of the above-mentioned planar coil, the lead-out conductor is in a region further inside than the above-mentioned planar coil and the above-mentioned first outer part provided on the first surface of the surface of the above-mentioned base part Electrode connection, the above-mentioned second lead-out conductor is connected to the above-mentioned second external electrode provided on the above-mentioned first surface of the above-mentioned base part, and the ends of the above-mentioned first lead-out conductor and the above-mentioned second lead-out conductor are from the above-mentioned first surface of the above-mentioned base part protrude, The first external electrode and the second external electrode form dome-shaped protrusions by covering the end portions of the first lead-out conductor and the second lead-out conductor. The coil component according to any one of claims 1 to 5, wherein the first lead-out conductor is linearly connected to the first external electrode from the first end of the planar coil. The coil component of claim 6, wherein the first lead-out conductor is parallel to the axis of the coil. The coil component according to claim 7, wherein the first lead-out conductor is arranged to overlap the coil conductor when the base portion and the planar coil are viewed from above in the axial direction of the coil. The coil component according to any one of claims 1 to 5, wherein the cross-sections of the first lead-out conductor and the second lead-out conductor in a direction perpendicular to the axis of the coil are circular. The coil component according to any one of claims 1 to 5, wherein the first lead-out conductor is connected to the first external electrode provided on the first surface of the base portion, and the second lead-out conductor is connected to the first lead-out conductor provided on the first surface of the base portion. The second external electrode is connected to the first surface of the base portion, and the first external electrode and the second external electrode are not provided on the second surface of the base portion opposite to the first surface. The coil component according to claim 10, wherein the first external electrode and the second external electrode are provided only on the first surface among the surfaces of the base portion. The coil component according to any one of claims 1 to 5, wherein the height of the coil component is 0.6 mm or less. An electronic device provided with the coil component according to any one of claims 1 to 12, and a circuit substrate for mounting or integrating the coil component.